Dr. Argo Masters, a psychotherapist in NYC, has just finished with his last patient for the day when he discovers a prospective client in his waiting room. It's late but he decides to see him. From the first instant of the intake he senses something is very different. When asked how he heard about Argo, the mysterious visitor provides details indicating an unexplainable level of knowledge. The client speaks obliquely about his personal history until finally, when pressed, stating that he is Satan. Argo takes this as clear evidence of psychosis, but his new client has anticipated this and...